Allocated but unannounced space
Every block here was allocated or assigned by a regional internet registry, and none of them appeared in any routing table we collected at our last snapshot — neither as a route of their own, nor covered by a larger announcement, nor carved up into more specifics.
“Unannounced” does not mean “unused”
Plenty of allocated space is deliberately kept off the public internet: private interconnects, lab and lawful-intercept ranges, networks reachable only inside one operator, and space held in reserve. Some of it is announced somewhere our collectors cannot see, which is a limit of our vantage points rather than a fact about the block.
It is also a snapshot, not a history: a block announced yesterday and withdrawn this morning appears here today. Nothing on this page means a block is unallocated, available, or free to announce.
Browse by registry
Browse by country
Countries with the most unannounced blocks, largest first.
Unannounced blocks
85,124 blocks match, ordered by prefix.
| Prefix | Addresses | Registry | Country | Allocated |
|---|---|---|---|---|
| 192.156.217.0/24 | 256 | RIPE NCC |  SC | 12th Nov 2019 |
| 192.156.221.0/24 | 256 | ARIN |  US | 5th May 1992 |
| 192.156.222.0/24 | 256 | ARIN | US | 5th May 1992 |
| 192.156.223.0/24 | 256 | ARIN | US | 5th May 1992 |
| 192.156.224.0/24 | 256 | ARIN | US | 5th May 1992 |
| 192.156.226.0/24 | 256 | ARIN | US | 8th May 1992 |
| 192.156.227.0/24 | 256 | RIPE NCC |  BE | 8th May 1992 |
| 192.156.229.0/24 | 256 | ARIN | US | 8th May 1992 |
| 192.156.231.0/24 | 256 | ARIN | US | 7th Mar 1996 |
| 192.156.239.0/24 | 256 | RIPE NCC |  GB | 18th May 1992 |
| 192.156.241.0/24 | 256 | ARIN | US | 28th May 1992 |
| 192.156.242.0/24 | 256 | ARIN | US | 28th May 1992 |
| 192.156.243.0/24 | 256 | ARIN | US | 28th May 1992 |
| 192.156.248.0/24 | 256 | RIPE NCC |  LU | 29th May 1992 |
| 192.156.250.0/24 | 256 | ARIN | US | 1st Jun 1992 |
| 192.156.253.0/24 | 256 | ARIN | US | 9th Jun 1992 |
| 192.156.254.0/24 | 256 | ARIN | US | 10th Jun 1992 |
| 192.156.97.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.98.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.156.99.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.157.1.0/24 | 256 | RIPE NCC |  NO | 15th Apr 1992 |
| 192.157.128.0/24 | 256 | ARIN | US | 14th Feb 1995 |
| 192.157.129.0/24 | 256 | RIPE NCC | NO | 14th Feb 1995 |
| 192.157.163.0/24 | 256 | ARIN | US | 14th Feb 1995 |
| 192.157.164.0/24 | 256 | ARIN |  CA | 14th Feb 1995 |
| 192.157.165.0/24 | 256 | RIPE NCC |  AT | 14th Feb 1995 |
| 192.157.166.0/23 | 512 | RIPE NCC | AT | 14th Feb 1995 |
| 192.157.168.0/24 | 256 | RIPE NCC | AT | 14th Feb 1995 |
| 192.157.169.0/24 | 256 | RIPE NCC | GB | 14th Feb 1995 |
| 192.157.170.0/24 | 256 | RIPE NCC | GB | 14th Feb 1995 |
| 192.157.171.0/24 | 256 | RIPE NCC |  DE | 14th Feb 1995 |
| 192.157.172.0/24 | 256 | RIPE NCC | GB | 14th Feb 1995 |
| 192.157.173.0/24 | 256 | ARIN | CA | 14th Feb 1995 |
| 192.157.174.0/24 | 256 | RIPE NCC | GB | 14th Feb 1995 |
| 192.157.175.0/24 | 256 | ARIN | US | 14th Feb 1995 |
| 192.157.176.0/24 | 256 | RIPE NCC | GB | 14th Feb 1995 |
| 192.157.177.0/24 | 256 | ARIN | US | 14th Feb 1995 |
| 192.157.184.0/24 | 256 | ARIN | US | 14th Feb 1995 |
| 192.157.185.0/24 | 256 | RIPE NCC |  IT | 14th Feb 1995 |
| 192.157.186.0/24 | 256 | ARIN | US | 14th Feb 1995 |
| 192.157.187.0/24 | 256 | RIPE NCC | GB | 14th Feb 1995 |
| 192.157.188.0/24 | 256 | ARIN | US | 14th Feb 1995 |
| 192.157.189.0/24 | 256 | RIPE NCC |  CH | 14th Feb 1995 |
| 192.157.190.0/24 | 256 | AFRINIC |  ZA | 14th Feb 1995 |
| 192.157.2.0/23 | 512 | RIPE NCC | NO | 15th Apr 1992 |
| 192.157.31.0/24 | 256 | ARIN | US | 26th May 1992 |
| 192.157.38.0/24 | 256 | ARIN | US | 16th Apr 1992 |
| 192.157.4.0/24 | 256 | ARIN | US | 15th Apr 1992 |
| 192.157.6.0/23 | 512 | ARIN | US | 4th Mar 2015 |
| 192.157.96.0/19 | 8.2k | ARIN | CA | 28th Jun 2013 |